From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Mon, 18 Feb 2019 13:32:45 -0600 Subject: [PATCH] BZ 1673167: Fix miscounting active paths When multipathd gets a change uevent, it calls pathinfo with DI_NOIO. This sets the path state to the return value of path_offline(). If a path is in the PATH_DOWN state but path_offline() returns PATH_UP, when that path gets a change event, its state will get moved to PATH_UP without either reinstating the path, or reloading the map. The next call to check_path() will move the path back to PATH_DOWN. Since check_path() simply increments and decrements nr_active instead of calculating it based on the actual number of active paths, nr_active will get decremented a second time for this failed path, potentially putting the multipath device into recovery mode. To avoid this situation, pathinfo() will now only set pp->state with DI_NOIO if DI_CHECKER is also set. This isn't set in uev_update_path() to avoid changing the path state in this case. Signed-off-by: Benjamin Marzinski --- libmultipath/discovery.c | 11 ++++++----- multipath/main.c | 2 +- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c index b267f07..5de087c 100644 --- a/libmultipath/discovery.c +++ b/libmultipath/discovery.c @@ -1914,11 +1914,12 @@ int pathinfo(struct path *pp, struct config *conf, int mask) if (path_state == PATH_REMOVED) goto blank; else if (mask & DI_NOIO) { - /* - * Avoid any IO on the device itself. - * Behave like DI_CHECKER in the "path unavailable" case. - */ - pp->chkrstate = pp->state = path_state; + if (mask & DI_CHECKER) + /* + * Avoid any IO on the device itself. + * simply use the path_offline() return as its state + */ + pp->chkrstate = pp->state = path_state; return PATHINFO_OK; } diff --git a/multipath/main.c b/multipath/main.c index 2c4054d..0545226 100644 --- a/multipath/main.c +++ b/multipath/main.c @@ -345,7 +345,7 @@ static int check_usable_paths(struct config *conf, pp->udev = get_udev_device(pp->dev_t, DEV_DEVT); if (pp->udev == NULL) continue; - if (pathinfo(pp, conf, DI_SYSFS|DI_NOIO) != PATHINFO_OK) + if (pathinfo(pp, conf, DI_SYSFS|DI_NOIO|DI_CHECKER) != PATHINFO_OK) continue; if (pp->state == PATH_UP && -- 2.17.2